The first hermit crab-associated sponge from South Africa, Suberites ambulodomus sp. nov. (Porifera, Demospongiae, Suberitida, Suberitidae), and its relationship with the hermit crab Pagurus liochele

Abstract

A new hermit crab–sponge association is reported from soft-bottom sediment at 35–50 m depth in St Francis Bay, off the south coast of South Africa, and the associated sponge, Suberites ambulodomus sp. nov. (Suberitida, Suberitidae), is described as a species that is new to science. This species grows a spirally curved chamber occupied by the hermit crab Pagurus liochele. Suberites ambulodomus sp. nov. differs from congeners in southern Africa by having tylostrongyle megascleres (in addition to tylostyles) and smooth centrotylote microstrongyle microscleres. In addition to these morphological characters, the molecular marker cox1 was used to confirm that all collected specimens were conspecific, and distinct from the recently described S. dandelenae Samaai et al., 2017 from South Africa’s west coast. This is the first report of a sponge–hermit crab association in southern Africa, which is suggested to be facultatively mutualistic. http://zoobank.org/urn:lsid:zoobank.org:pub:D6C2BAC9-7F30-4CE4-908E-17FB9B8F5102

Key words:

• cox1
• hermit crab association
• morphology
• new species
• Porifera
• South Africa
• Suberitidae

Acknowledgements

We are grateful to the (then) South African DAFF demersal survey team, captain and crew involved in the collection of the F/V Compass Challenger. The Oceans and Coasts Research Chief Directorate, Department of Forestry, Fisheries and Environment (DFFE), is gratefully acknowledged for logistic support, as well as the National Research Foundation (NRF) for financial support to TS (grant 141960), which covered sequencing costs under the Marbibi-SA programme. RP as a PhD candidate was funded by an NRF ACEP (African Coelacanth Ecosystem Programme) bursary, under the Imida Frontiers Project (Principal Scientist: Sven Kerwath of the DFFE). Funding that enabled JL to participate in this research was provided through the Sea Change Trust and performed with the support of Keystone Grant 542 – 1001 Seaforest Species – from the Save Our Seas Foundation. We thank Anton du Plessis for support with the microCT scanning and imaging. We also thank Miranda Waldron (Electron Microscope Unit, University of Cape Town) for providing access to, and assistance with, the scanning electron microscope. Raquel Pereira (currently at Uppsala University, Sweden) has been especially helpful regarding collaboration and discussions on this difficult sponge genus. Finally, we would like to thank the two anonymous reviewers who provided valuable feedback to improve this manuscript.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Associate Editor: Dr Ana Riesgo